It looks like s390 is the only arch that uses a #else (CONFIG_COMPAT) somaybe it is the only breakage.

Perhaps using a function instead of a define in include/linux/compat.hand removing the else from arch/s390/include/asm/compat.h is thesensible thing to do here or maybe just removing the #else fromarch/s390/include/asm/compat.h since it just returns 0 anyway?